1. technology and computing

In this monthly column, Ric Peri of the AEA’s Washington, D.C. office, informs members of the latest regulatory updates.
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v i c e p r e s i d e n T o f G o v e r n m e n t & IND U S T RY A f f a i r s f o r a e a
A Very Important Question: Why?
R
ecently, I received a call from a
longtime acquaintance who was
having another “discussion” with
his local FAA office. He had performed
an alteration using the AEA’s “Evaluating
an Alteration” checklist and came to the
conclusion that the alteration was a minor
alteration.
As many similar conversations often
begin, he explained the alteration to me
and added that his inspector wanted him
to record the alteration on an FAA Form
337. And, oh by the way, get the data field
approved, too.
And my question was: Why?
Without a doubt, “why” is one of the
most important questions you can ask.
The basis for the aviation safety inspector
“recommending” a field approval may be
that the inspector’s previous experience
included a similar installation that was
field approved. Or, maybe there is recent
guidance that tells the inspector to address these types of alterations. Or, maybe the inspector just has a philosophy that
any alteration is major, regardless of what
the regulations say. Therefore, “why” is a
very important question.
Asking why is not a question that challenges authority. But, rather it is a question to discover what “they know” that
you hadn’t considered or what they hadn’t
considered. As it turned out, in this case
the “applicant” had not considered all of
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2011
the issues and after we walked through
the process, asked the questions and evaluated the products (a non-approved PFD),
the FSDO was more right than the applicant. In fact, the alteration was major.
If you have an inspector who believes
that all alterations are major, don’t waste
your time arguing your case. Simply take
the issue up the chain of command and
have a discussion with the supervisor and/
or office manager. The regulations are
clear. There are three levels of changes to
type certificated products: a major change
in type design, which requires an application for an STC; a major alteration, which
requires approved data; and, a minor alteration. If your inspector doesn’t recognize all three changes supported by the
regulations, then start up the supervisory
chain until you reach a supervisor who
recognizes the regulations.
For the benefit of our international
members, an alteration and a modification
are not synonymous. Technically, a major
mod is a “major change in type design.”
A major mod is treated the same worldwide. With few exceptions, they require
a supplemental type certificate (14 CFR
21.93). Unique to the FAA system, minor mods are divided into major and minor alteration. Over the years, there have
been a number of cases where a major
alteration really should have been treated
as a major change in type design (major
mod) and should have been performed
via an STC, but these cases are rare. The
one significant difference in major mods
comes from the treatment of flight manual supplements. In the FAA system, the
FMS is amended as a result of the change.
It does not, in and of itself, create a need
for an STC. On the other hand, many other authorities consider the FMS change a
change to the aircraft and can, by itself,
generate the need for an STC.
Because the regulations are clear that
an STC is higher than a major alteration,
and a major alteration is higher than a minor alteration, we perform a “top-down”
analysis for an alteration starting at the
highest level of approval (STC) and work
down through the regulations. If at any
point of the analysis you answer affirmative to a question, the change is defined at
that level of the regulation.
The logic of the evaluation is simple,
and the regulations are clear. “A minor
alteration means an alteration other than
a major alteration.” And, as has been
told many times, the criterion for a major alteration is defined by regulation. As
a result, the AEA was able to develop a
checklist that is widely used in evaluating an alteration. The checklist is based
on the regulations and follows the alteration logic of FAA Advisory Circular
(AC) 43-210, Standardized Procedures
for Requesting Field Approval of Data,
Asking why is not a question that challenges authority.
But, rather it is a question to discover what ‘they know’
that you hadn’t considered or what they hadn’t considered.
Major Alterations and Repairs. (The AEA
checklist is an exclusive member tool and
can be found on the members-only section of the AEA website: www.aea.net.)
Generally speaking, if the alteration does
not meet at least one criterion of a major
change in type design or a major alteration, the alteration is minor. However, like
life, there are always exceptions.
For those who regularly use the AEA
checklist, Decision Tree for Avionics Alterations, the final two items require research into policy. If you get to the last
two items, the alteration does not meet
the strict regulatory requirement of a
higher level alteration. However, § 21.95
says that minor changes in a type design
are approved under a method acceptable
to the FAA. So, while an alteration may
be technically minor, the Administrator
can, and regularly does, require that an
alteration be treated as if it were major.
A good place to start your search for
policy is FAA Order 8900.1, Volume 4,
Chapter 9, Selected Field Approvals. Figure 4-68 is titled, Major Alterations Job
Aid. The job aid is divided into four sections: general aviation aircraft; rotorcraft;
transport airplanes; and engines, propellers and APUs. If you “ask” your ASI for
their opinion about a particular alteration,
this job aid will guide your inspector. As a
result, it also provides good guidance for
the applicant. If the job aid requires an al-
teration to be accomplished via an STC,
the Administrator has deemed that this
type of alteration should be treated as if it
were a major change in type design.
For example, according to FAA policy, the installation of avionics systems
that are intended to perform critical functions, or involving complex interfaces
to other systems, require an STC, as do
head-up displays, enhanced flight vision
systems, synthetic vision systems used
for primary navigation and traffic alert
and collision avoidance systems II.
There also are two classifications of
alterations listed in the job aid to pay
particular attention to: EVL and ENG.
When an item is listed with either of
these codes, the applicant should consider not applying for a field approval,
but rather use an appropriately rated
DER. Flight Standards ASI’s have not
been delegated authority to approve data
for every alteration. These codes indicate
types of alterations that require the ASI
to seek support from their Aircraft Certification Office. As anyone knows who
has had to work one of these coordinated
field approvals, the time expectations
can be prohibitive. You will save money
by seeking a qualified DER for these
projects and bypassing data approvals at
the local FSDO.
For example, all terrain awareness and
warning systems (TAWS-A and TAWS-
B) not listed in FAA InFO 08047 require
that the alteration be EVL (evaluated)
before a field approval may be granted.
This clearly would require the involvement and coordination of a second FAA
office (ACO). To minimize the delays and
impact to your customer, this is a prime
candidate for a DER data approval.
You also need to review ACs for pertinent guidance. For instance, AC 20-138A
requires that although there are several
Technical Standard Orders that apply to
the design and certification of GNSS systems, the AC requires that each TSO’d
article obtain a first-time airworthiness
approval through TC or STC.
Please note: GNSS (Global Navigation Satellite System) is a generic term
for satellite-based navigation, including
GPS, SBAS, GBAS, GLONASS and any
other satellite navigation system.
The AC continues to address subsequent installations. According to the AC,
“For installation of TSO’d articles after
the first-time STC, the extent of FAA involvement and review for a given installation depends on the characteristics of
the installation.” The AC continues with
guidance that the installation should be
evaluated to classify the installation and determine the type of approval vehicle. The
AC guidelines follow consistent FAA phiContinued on page 41
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Duncan_ Satellite_Feb 16 2011.pdf 1 2/16/2011 10:20:53 AM
The View from Washington
Continued from page 19
losophy of a top-down analysis from major
change to type design, to major alteration
and, finally, minor alteration. This is one of
those areas where many ASI’s have failed
to keep up with the latest guidance, or in
some cases, reject headquarters’ guidance
altogether.
Under the original AC 20-138, installation of GPS equipment required the use
of approved data under an STC or major
alteration, because GPS was a new and
unique technology. However, since GPS
technology is now common and considerable experience has been obtained in the installation of GPS, the FAA has made it clear
that approved data for every installation is
no longer appropriate. Instead, installations that do not qualify as major alterations
above should be accomplished as minor
alterations.
This guidance also is applicable to
WAAS upgrades of previously installed
equipment.
An often overlooked item in the AC addresses GNSS equipment that is installed
for VFR use only or in aircraft that are not
approved for IFR use. GNSS equipment
may be installed on a no-hazard basis as a
supplement to VFR navigation. GNSS installations limited to VFR use only should
be evaluated under the same criteria as described above.
So, back to the original alteration. The
physical alteration to add VFR only, noninterference avionics was minimal. However, the policy regarding the installation
of this type of equipment shows that the
administrator wants all such installations to
be treated as if they were major. And, once
this happens, the data to support the conformity of the non-approved PFD, in addition
to the alteration data, was also required to
be approved.
As a result, this “cheap” alternative
proved to be more expensive that using an
available certified products under the provided AML-STC. q
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